Rewrite TemplateURLService's SyncableService implmentation to avoid sending ACTION_DELETEs to Sync.

This rewrite should make MergeDataAndStartSyncing more robust, resulting in fewer underscore dupes and hopefully fewer SyncErrors, as we are more careful about when we send ACTION_UPDATEs during initial merge.

Update unit tests to reflect these changes.

BUG=140732
TEST=Sync two clients with different search engine entries and ensure that they end up in sync. Try to add, update, or remove entries from one client and expect the same to occur on the other.


Review URL: https://chromiumcodereview.appspot.com/10826309

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@151569 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/search_engines/template_url_service.h

@@ -352,17 +352,11 @@ class TemplateURLService : public WebDataServiceConsumer,
                            CreateTemplateURLFromSyncData);
   FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest, UniquifyKeyword);
   FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest,
-                           SyncKeywordConflictNeitherAutoreplace);
+                           ResolveSyncKeywordConflict);
+  FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest, PreSyncDeletes);
   FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest,
-                           SyncKeywordConflictBothAutoreplace);
-  FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest,
-                           SyncKeywordConflictOneAutoreplace);
-  FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest,
-                           FindDuplicateOfSyncTemplateURL);
-  FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest,
-                           MergeSyncAndLocalURLDuplicates);
-  FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest,
-                           PreSyncDeletes);
+                           IsLocalTemplateURLBetter);
+  FRIEND_TEST_ALL_PREFIXES(TemplateURLServiceSyncTest, MergeInSyncTemplateURL);
 
   friend class TemplateURLServiceTestUtil;
 
@@ -532,49 +526,46 @@ class TemplateURLService : public WebDataServiceConsumer,
   // execute the special character appending functionality.
   string16 UniquifyKeyword(const TemplateURL& turl, bool force);
 
-  // Given a TemplateURL from Sync (cloud) and a local, non-extension
-  // TemplateURL with the same keyword, selects "better" and "worse" entries:
-  //   * If one of the TemplateURLs is replaceable and the other is not, the
-  //     non-replaceable entry is better.
-  //   * Otherwise, if |local_turl| was created by policy, is the default
-  //     provider, or was modified more recently, it is better.
-  //   * Otherwise |sync_turl| is better.
-  // Then resolves the conflict:
-  //   * If the "worse" entry is |sync_turl|, and it is replaceable, add a
-  //     syncer::SyncChange to delete it, and return false.
-  //   * If the "worse" entry is |local_turl|, and it is replaceable, remove it
-  //     from the service and return true.
-  //   * Otherwise, uniquify the keyword of the "worse" entry.  If it is
-  //     |local_turl|, update it within the service.  Add a SyncChange to update
-  //     things (always for |sync_turl|, sometimes for |local_turl|; see
-  //     comments in implementation), and return true.
-  // When the function returns true, callers can then go ahead and add or update
-  // |sync_turl| within the service.  If it returns false, callers must not add
-  // the |sync_turl|, and must Remove() the |sync_turl| if it was being updated.
-  // (Be careful; calling Remove() could add an ACTION_DELETE sync change, which
-  // this function has already done.  Make sure to avoid duplicates.)
-  //
-  // Note that we never call this for conflicts with extension keywords because
-  // other code (e.g. AddToMaps()) is responsible for correctly prioritizing
-  // extension- vs. non-extension-based TemplateURLs with the same keyword.
-  bool ResolveSyncKeywordConflict(TemplateURL* sync_turl,
-                                  TemplateURL* local_turl,
+  // Returns true iff |local_turl| is considered "better" than |sync_turl| for
+  // the purposes of resolving conflicts. |local_turl| must be a TemplateURL
+  // known to the local model (though it may already be synced), and |sync_turl|
+  // is a new TemplateURL known to Sync but not yet known to the local model.
+  // The criteria for if |local_turl| is better than |sync_turl| is whether any
+  // of the following are true:
+  //  * |local_turl|'s last_modified timestamp is newer than sync_turl.
+  //  * |local_turl| is created by policy.
+  //  * |local_turl| is the local default search provider.
+  bool IsLocalTemplateURLBetter(const TemplateURL* local_turl,
+                                const TemplateURL* sync_turl);
+
+  // Given two synced TemplateURLs with a conflicting keyword, one of which
+  // needs to be added to or updated in the local model (|unapplied_sync_turl|)
+  // and one which is already known to the local model (|applied_sync_turl|),
+  // prepares the local model so that |unapplied_sync_turl| can be added to it,
+  // or applied as an update to an existing TemplateURL.
+  // Since both entries are known to Sync and one of their keywords will change,
+  // an ACTION_UPDATE will be appended to |change_list| to reflect this change.
+  // Note that |applied_sync_turl| must not be an extension keyword.
+  void ResolveSyncKeywordConflict(TemplateURL* unapplied_sync_turl,
+                                  TemplateURL* applied_sync_turl,
                                   syncer::SyncChangeList* change_list);
 
-  // Returns a TemplateURL from the service that has the same keyword and search
-  // URL as |sync_turl|, if it exists.
-  TemplateURL* FindDuplicateOfSyncTemplateURL(const TemplateURL& sync_turl);
-
-  // Given a TemplateURL from the cloud and a local matching duplicate found by
-  // FindDuplicateOfSyncTemplateURL, merges the two. If |sync_turl| is newer,
-  // this replaces |local_turl| with |sync_turl| using the service's Remove and
-  // Add. If |local_turl| is newer, this replaces |sync_turl| with |local_turl|
-  // through through adding appropriate SyncChanges to |change_list|. This
-  // method takes ownership of |sync_turl|, and adds it to the model if it is
-  // newer, so the caller must release it if need be.
-  void MergeSyncAndLocalURLDuplicates(TemplateURL* sync_turl,
-                                      TemplateURL* local_turl,
-                                      syncer::SyncChangeList* change_list);
+  // Adds |sync_turl| into the local model, possibly removing or updating a
+  // local TemplateURL to make room for it. This expects |sync_turl| to be a new
+  // entry from Sync, not currently known to the local model. |sync_data| should
+  // be a SyncDataMap where the contents are entries initially known to Sync
+  // during MergeDataAndStartSyncing.
+  // Any necessary updates to Sync will be appended to |change_list|. This can
+  // include updates on local TemplateURLs, if they are found in |sync_data|.
+  // |initial_data| should be a SyncDataMap of the entries known to the local
+  // model during MergeDataAndStartSyncing. If |sync_turl| replaces a local
+  // entry, that entry is removed from |initial_data| to prevent it from being
+  // sent up to Sync.
+  // This should only be called from MergeDataAndStartSyncing.
+  void MergeInSyncTemplateURL(TemplateURL* sync_turl,
+                              const SyncDataMap& sync_data,
+                              syncer::SyncChangeList* change_list,
+                              SyncDataMap* local_data);
 
   // Checks a newly added TemplateURL from Sync by its sync_guid and sets it as
   // the default search provider if we were waiting for it.